Always display environment selector

On the metrics dashboard, always display the environment selector,
even if there is no data to display for that environment. This allows
the user to switch to the metrics dashboard of another environment.

3 files changed, 78 insertions, 11 deletions

diff --git a/spec/features/projects/environments/environment_metrics_spec.rb b/spec/features/projects/environments/environment_metrics_spec.rb
index edbab14f7c1..b08ccdc2a7c 100644
--- a/spec/features/projects/environments/environment_metrics_spec.rb
+++ b/spec/features/projects/environments/environment_metrics_spec.rb
@@ -9,11 +9,11 @@ describe 'Environment > Metrics' do
   let(:build) { create(:ci_build, pipeline: pipeline) }
   let(:environment) { create(:environment, project: project) }
   let(:current_time) { Time.now.utc }
+  let!(:staging) { create(:environment, name: 'staging', project: project) }
 
   before do
     project.add_developer(user)
-    create(:deployment, environment: environment, deployable: build)
-    stub_all_prometheus_requests(environment.slug)
+    stub_any_prometheus_request
 
     sign_in(user)
     visit_environment(environment)
@@ -23,15 +23,50 @@ describe 'Environment > Metrics' do
     Timecop.freeze(current_time) { example.run }
   end
 
+  shared_examples 'has environment selector' do
+    it 'has a working environment selector', :js do
+      click_link('See metrics')
+
+      expect(page).to have_metrics_path(environment)
+      expect(page).to have_css('div.js-environments-dropdown')
+
+      within('div.js-environments-dropdown') do
+        # Click on the dropdown
+        click_on(environment.name)
+
+        # Select the staging environment
+        click_on(staging.name)
+      end
+
+      expect(page).to have_metrics_path(staging)
+
+      wait_for_requests
+    end
+  end
+
+  context 'without deployments' do
+    it_behaves_like 'has environment selector'
+  end
+
   context 'with deployments and related deployable present' do
+    before do
+      create(:deployment, environment: environment, deployable: build)
+    end
+
     it 'shows metrics' do
       click_link('See metrics')
 
       expect(page).to have_css('div#prometheus-graphs')
     end
+
+    it_behaves_like 'has environment selector'
   end
 
   def visit_environment(environment)
     visit project_environment_path(environment.project, environment)
   end
+
+  def have_metrics_path(environment)
+    have_current_path(metrics_project_environment_path(project, id: environment.id))
+  end
 end
diff --git a/spec/javascripts/monitoring/dashboard_spec.js b/spec/javascripts/monitoring/dashboard_spec.js
index f4166987aed..cf72cce1781 100644
--- a/spec/javascripts/monitoring/dashboard_spec.js
+++ b/spec/javascripts/monitoring/dashboard_spec.js
@@ -62,16 +62,34 @@ describe('Dashboard', () => {
   });
 
   describe('no metrics are available yet', () => {
-    it('shows a getting started empty state when no metrics are present', () => {
+    beforeEach(() => {
       component = new DashboardComponent({
         el: document.querySelector('.prometheus-graphs'),
         propsData: { ...propsData },
         store,
       });
+    });
 
+    it('shows a getting started empty state when no metrics are present', () => {
       expect(component.$el.querySelector('.prometheus-graphs')).toBe(null);
       expect(component.emptyState).toEqual('gettingStarted');
     });
+
+    it('shows the environment selector', () => {
+      expect(component.$el.querySelector('.js-environments-dropdown')).toBeTruthy();
+    });
+  });
+
+  describe('no data found', () => {
+    it('shows the environment selector dropdown', () => {
+      component = new DashboardComponent({
+        el: document.querySelector('.prometheus-graphs'),
+        propsData: { ...propsData, showEmptyState: true },
+        store,
+      });
+
+      expect(component.$el.querySelector('.js-environments-dropdown')).toBeTruthy();
+    });
   });
 
   describe('requests information to the server', () => {
@@ -150,14 +168,24 @@ describe('Dashboard', () => {
         singleGroupResponse,
       );
 
-      setTimeout(() => {
-        const dropdownMenuEnvironments = component.$el.querySelectorAll(
-          '.js-environments-dropdown .dropdown-item',
-        );
+      Vue.nextTick()
+        .then(() => {
+          const dropdownMenuEnvironments = component.$el.querySelectorAll(
+            '.js-environments-dropdown .dropdown-item',
+          );
 
-        expect(dropdownMenuEnvironments.length).toEqual(component.environments.length);
-        done();
-      });
+          expect(component.environments.length).toEqual(environmentData.length);
+          expect(dropdownMenuEnvironments.length).toEqual(component.environments.length);
+
+          Array.from(dropdownMenuEnvironments).forEach((value, index) => {
+            if (environmentData[index].metrics_path) {
+              expect(value).toHaveAttr('href', environmentData[index].metrics_path);
+            }
+          });
+
+          done();
+        })
+        .catch(done.fail);
     });
 
     it('hides the environments dropdown list when there is no environments', done => {
@@ -212,7 +240,7 @@ describe('Dashboard', () => {
       Vue.nextTick()
         .then(() => {
           const dropdownItems = component.$el.querySelectorAll(
-            '.js-environments-dropdown .dropdown-item[active="true"]',
+            '.js-environments-dropdown .dropdown-item.is-active',
           );
 
           expect(dropdownItems.length).toEqual(1);
diff --git a/spec/support/helpers/prometheus_helpers.rb b/spec/support/helpers/prometheus_helpers.rb
index 87f825152cf..db662836013 100644
--- a/spec/support/helpers/prometheus_helpers.rb
+++ b/spec/support/helpers/prometheus_helpers.rb
@@ -70,6 +70,10 @@ module PrometheusHelpers
     WebMock.stub_request(:get, url).to_raise(exception_type)
   end
 
+  def stub_any_prometheus_request
+    WebMock.stub_request(:any, /prometheus.example.com/)
+  end
+
   def stub_all_prometheus_requests(environment_slug, body: nil, status: 200)
     stub_prometheus_request(
       prometheus_query_with_time_url(prometheus_memory_query(environment_slug), Time.now.utc),